Needle bed for knitting machines



3,1938. CSCHURICHTI 2,127,537

NEEDLE BED FOR KNITTING MACHINES Filed April 11, 1936 2 Shets-Sheet l 2/I 22 20 v l N l\ w 'I A INVENTOR Carl Schurichf ATTORNEY A gc. scHumcHT2,127,537

NEEDLE BED FOR KNITTING MACHINES Filed April 11, 1936 2 Sheets-Sheet 2Fig.9

INVENTOR gYarl Schur-ichf ATTO R N EY Patented Aug. 23, 1938 NEEDLE BED'FOR KNITTING MACHINES Carl Schuricht, Hollis, N. Y., assignor to Max B.

. Nydegger, Summit, N. J.

Application April 11.

8 Claims.

The present invention relates to knitting machines generally and moreparticularly the invention relates to such machines of the typecomprising at least two needle beds mounted in ad- I -.'|acent positionswith an open passage for the yarn and fabric therebetween.

The usual type of needle bed now in use in the flat bed type of knittingmachine consists of an elongated, rectangular metal plate having aplurality of grooves milledtherein which support the needles and theneedle jacks and guide the movements of these elements duringtheoperation of the machine.

The grooves in the needle bed are at right angles to the longer sides ofthe needle bed and extend thereacross. Hereinafter the long side of theneedle bed adjacent the corresponding side of the other needle bed willbe termed the work side since that is the side whereat the work, thatao'is, the knitting of the yarn, takes place The bottom of each grooveis a plane and the maximum depth of the groove is at each end thereof. Ashort distance back from the work side of the needle bed the sides ofthe grooves are reduced to 25 their minimum depth and the depth thereofincreases in a series of steps as the distance from the work sideincreases. At an appreciable distance from the work side of the needlebed the grooves are again at their maximum depth to guide the needlejacks. One end of each side of each groove is contiguous with the workside of the bed and serves as an immovable post around which the yarn ispulled into the groove by the needle during the operation of theknitting machine. This post is known in the art as a tooth and will beidentified hereinafter. by that term. The grooves are at their maximumwidth at the work side of the bed and the width thereof is reduced toslightly more than the width of the needle jack at the end of theminimum depth part of the groove.

There are many disadvantages connected with the type of needle beddescribed above and which are at present in extensive use in the art.From the standpoint of manufacture of the needle bed the material fromwhich the entire bed is made is controlled by the material best suitedfor the teeth. Inasmuch as the teeth are apt to be struck withconsiderable force and bent when a needle is accidentally lifted up fromthe bottom of the groove andhit by the needle actuating means travelingover the needle bed a ductile material is best suited for the teethsince the teeth can be forced back into position after being bent.

This type of material does not lend itself;"

1936, Serial No. 73,895

as readily to the milling of the grooves as does a harder material.Another disadvantage of making the teeth integral with the needle bed isthat the finishing and polishing of the surfaces of the teeth and thegrooves across which the yarn is pulled is a dlfl'lcult and expensivehand operation due to the narrow width ofthe grooves and is one inwhichthe highest degree of skill produces inaccurate and imperfect results.The importance of having smooth surfaces of the same geometricconfiguration on the teeth and the other parts of the needle bedacrosswhich 'the yarn is pulled during the operation of the machine isapparent when it is realized that the yarn worked upon by the machineconsists of a large number of twisted fibers, frequently has a roughsurface and frequently does not have a large tensile strength. Further,when knitting certain types of stitches the yarn is pulled back andforth over as many as four teeth and into three grooves. Obviously underthese conditions the surfaces of the teeth and the-other parts of theneedle bed in contact with the yarn must be as smooth as possible toavoid catching the fibers of the yarn and of such configuration that itoffers a minimum resistance to the travel of the yarn thereacross. Aspointed out above the formation of these surfaces of the needle bed andthe polishing thereof by hand is a difficult and expensive operation andimperfect results are obtained.

While it has not' been emphasized above there is considerable wear onthe teeth and the other surfaces of the needle bed across which the yarnis pulled during the operation of the machine and while there are manymaterials more resistant to this wear than a ductile material thenecessity for ductility in the teeth has dictated the choice of thematerial used for the parts of the needle bed in contact with the yarn.

From the foregoing it isbelieved to be apparent that the needle beds nowin use in the art represent a compromise and that the, materials bestsuited forthe various parts of the needle bed, both from amanufacturingstandpoint and from the standpoint of the use made of the parts in theoperation of the knitting machine, have not been employed heretofore.

The object of the present invention is to provide a needle bed for aknitting machine which is inexpensive to manufacture, is easilyrepaired, and which has a long useful life. Another object of theinvention is to provide a needle bed like parts of which have the samegeometric configurationand a configuration best suited for its purpose.Still another object of the invention is to provide a needle bed thevarious parts of which are in such relation to each other that theoperation of racking the knitting machine, by which is meant thelongitudinal displacement of one needle bed with respect to the other,is facilitated. A further object of the invention is to provide a needlebed of such structure that .many types of stitches impossible offormation on machines comprising needle beds of the prior art aresuccessfully knitted. A still further object of the invention is toprovide a needle bed of such structure that many types of yarns,filaments, or ribbons heretofore useless in connection with knittingmachines are successfully knitted by such machines. Still furtherobjects and advantages attaching to the device and to its use andoperation will be apparent to those skilled in the art from thefollowing particular description.

The invention attains its objects by making the teeth separable from theneedle bed and by providing removable means on the needle bed to rigidlysupport the teeth in their proper position on said bed. The teeth areeasily inserted into and removed from said supporting means. The teethand the needle bed can thus be manufactured separately and be made ofdifferent materials better suited to the manufacturing processes and theuse to which each of these elements are subjected. For example, the partof the needle bed in which the grooves for the needle jacks are milledcan be made of a harder material better suitedto milling than was thepractice heretofore when the teeth were made integral with the otherparts of the needle bed. The teeth can be made and polished by massproduction methods in a uniform, perfect shape more suitable for itspurpose than was possible by the manual methods inuse prior to thepresent invention. The smooth, perfectly formed surface of the machinemade teeth offers a minimum of resistance.

to the yarn and obviates catching of the fibers which makes possible thesuccessful knitting of a large number of rough, large fibered yarns andyarns, filaments, or ribbons of low tensile strength or limitedflexibility and elasticity which could not be successfully worked uponby knitting machines having needle beds in which the teeth were madeintegral with the other parts thereof due to the comparatively rough andimperfectly shaped teeth of such prior needle beds.

Another advantage of the needle bed made in accordance with the presentinvention is the ease and celerity with which damaged teeth may berepaired or replaced. When the teeth are accidentally bent in needlebeds having the teeth integral therewith it has beenthe practice to bendthe teeth back into shape. The ductility of the teeth made such bendingpossible. The bending of the teeth and the impact of the needles on theteethleft a rough surface which had to be carefully smoothed down byhand in order to avoid catching of the yarn. This polishing operationwas imperfect at best and took considerable time, the machine standing.idle while this operation was performed. Further, after the teeth hadbeen bent and repaired a number of times they were considerably weakenedand broke off at the joint therebetween which would catch the yarn andbreak it. This takes considerable time, requires highly skilled laborand frequently necessitates the removal of the needle bed from themachine. When the tooth is made separable from the needle bed, inaccordance with the present invention, a damaged tooth is easily removedfrom the needle bed, a perfect tooth is inserted in its proper positiontherein'without disturbing any of the other parts of the machine and themachine is again ready for use. This operation requires littlemechanical skill and can be performed by the operator of the knittingmachine.

The invention will be readily understood from an inspection of thedrawings accompanying and forming part of this specification and from apcrusal of the following detailed description thereof.

' strip useful in the embodiment ofthe invention illustrated in Figs. 2and 3, showing the teeth in position therein,

Fig. 5 is a. perspective view ofthe preferred form of tooth useful inthe embodiment of the invention illustrated in Figs. 2 to 5,

Fig. 6 is a fragmentary end view of the preferred embodiment of theinvention,

Fig. 7 is a fragmentary top view of the embodiment of the inventionillustrated in Fig. 6,

Fig. 8 is a side elevational -view of the preferred form of tooth usefulin"the embodiment of the invention shown in Figs. 6' and 7, and

Fig. 9 is a top view of the tooth shown in Fig. 8. Like numbers denotelike parts in all the figures. Referring to Fig. 1 of the drawings eachof the needle beds l illustrated consists of an elongated, rectangularplate having a plurality of grooves or slots extending across the widththereof which guide the movements of the needle 20 and the 'needle jack2| which connects the needle 20 with the actuating means during theoperation of the machine. The slots in the needle beds are in alignmentso that the needles 20 can slide from one needle bed to the other informing certain stitches. It will be noted that the teeth 22 areintegral with the slotted. part of the needle beds I. The disadvantagesof such structure, both from a manufacturing standpoint and in the useof the machine, have been pointed out above. It

will be noted further that the slot terminates in a plane passingthrough the work face of the tooth. The disadvantages of this structurewill be pointed out below.

In the embodiment of the invention illustrated in Figures 2 to 5 of thedrawings the needle bed I consists of an elongated, rectangular metalplate I having a plurality of slots 2 milled therein in the manner nowknown in the art. The

height of the ridges 3 separating the slots diminishes in a series ofsteps from the back face to the forward work face of the bed I, as shownin Fig. 2. The lowest step, H which terminates at the work face of theneedle bed I, is thinner than the other steps, as shown in Fig. 3, andis just sumcient in height to guide the needle an the yarn in theirmovements therein.

The underside of the work face of the needle bed I is cutout in the formof a rabbet (Fig. 2)

(Fig. .4). The holding strip 4 is fastened to the needle bed I bya'plurality of threaded bolts 1 which are inserted in the counter-sunkholes 8 of the holding strip 4 and screwed into threaded holes in'theunderside of the needle bed I. The holes 8 and the threaded holesin theneedle bed are in such position that the grooves are directly underneaththe ridges 3. so that the vertical part II of each tooth 6 is in linewith one of the ridges 3 when. these elements are assembled to form aunit. The height of the part 9 of each of the teeth 6 in the slots"5 ,ofthe holding strip 4 is equal to the depth of said slots 5 and extends aconsiderable distance along said slot 5 so that when the holding strip 4is fastened to the needle bed I the tooth 6 is rigidly held in itsproper in Fig. 5 of the drawings. The'metalused for the tooth 6 is aharder and more resilient one.

than is practical to use for this part in the type of needle bedillustrated in Fig. lgwhich must be of a ductile metal. The hardermaterial of the teeth 6 makes possible the knitting of many materials,such as metal filaments, which could .not

the tooth 6 a blank is first stamped out which 'is' then bent or foldedback on itself to form the tooth 6 illustrated in Fig. 5 which issmoothed and polished after the bending operation. The: folding of theblank forms a rounded front face on the upper part II of the tooth 6 issmooth and is contiguous with the work face of the grooved por- 'tion Iof the needle bed to avoid an opening between these surfaces which wouldcatch the fibers of the yarn. The back portion of lower part 9 of thetooth 6 is flared in a V shape so that when the said part 9 is insertedin the grooves 5 of the holding strip'4 the sides thereof presstightlyagainst the sides of the grooves 5 to resist any force tendingtopull said tooth" 6 outof the groove 5.

In the event that any of the teeth 6 are bent out of shape or brokenduring the operation of the machine the removal thereof from the needlebed and the replacement thereof with another perfect tooth isaccomplished "by removing the holding strip 4 from the needle bed, whichis accomplished without disturbing any of the other parts of theknitting machine, extracting the damaged tooth or teeth from the grooves5, inserting a perfect tooth in the grooves 5, and replacing the holdingstrip 4 on the needle-bed I. This repair of the machine can be done bythe operatorthereof since it requires mechanical skill well within thatpossessed by the average operator of knitting machines and isaccomplished in ash'ortftime.

The preferred embodiment. of the invention is illustrated in Figs. 6 to9 of the drawings. In

this embodiment of the invention the slotted part of the needle bed Iterminates at the part thereof whereat the ridges begin to decrease inwidth in the usual type of needle bed to forni the wider part of theslot into which the yarn is pulled by I the needles. The grooved part I5of the holding strip 4 is of sufficient height that the top surfacethereof between the grooves is in the same plane 4 as the bottom of thegrooves in the needle bed I and supports the needle and the yarn. Theparts 9 of the teeth 6 extend beyond the top surface of the holdingstrip 4 to form the sides of grooves. The back surface of the slottedpart of the holding strip 4 is separated from the adjacent surface ofthe needle bed I a distance sufficient to permit the insertion of theflared parts III of the teeth 6 therebetween, as shown in Figs. 7 and 8.

In this embodiment of the invention the flared parts III of the teeth 6are greater in height than the 'part 9 thereof in the slots of theholding strip 4, as shown in Figs. 6 and 8, and when the variouselements of this embodiment of the invention are assembled the top ofthe parts III are in the same plane as the top of the contiguous part ofthe ridge 3 of the needle bed as shown in Fig. 6.

As the needle is moved along the slot 2 of "the knitting machine it isfrequently forced against the sides of said slots 2 and the end thereofstrikes and rubs against the part of the slot 2 whereat the width of theslot grows smaller.

on the flared part III of the teeth 6 rather than the needle bed itselfwhich prolongs the useful life of the slotted part of the needle bed I.The

bottom parts I6 of the teeth 6 protrude beyond,

the back edge of said teeth 6 and when the holder 4, and the teeth 6 areassembled on the needle bed I the protruding lower part of .the teeth 6fit into a rabbet in the needle bed I, as shown in Fig. 6. The holdingstrip 4 is rigidly attached to the needle bed I by the screws I and theteeth 6 are immovably held in position by the-structure described above.

The element I3 of the embodiment of the invention illustrated in Figs. 6and '7 is a wire which. is drawn through a perforation I2 in each of theteeth 6, which perforations I2 are in alignment when the teeth 6 aremounted in position in the holding strip 4. The diameter of the wire I3so The wear; incident to this striking and rubbing is exerted closelyapproaches .that of the perforations I2,

that the surface of the wire is contiguous with that of the perforationsI2. Catching of the yarn betweensaid surfaces is thus an impossibility.The wire I3 is slightly below the plane of the upper surfaces of theholding strip 4 and is.

. recessed slightly from the rounded front face of the teeth 6. In thisposition the wire I3 is sub- .force exerted on the needles-by the weightcustomarily attached to the knitted fabric is exerted vertically ratherthan in a direction at an angle to the vertical and toward the oppositeneedle bed as in the prior types of needle beds in which the work faceof the needle bed is in the same plane as the front surface of theteeth. This has been a source of considerable difliculty in knittingmachines in the past due to the fact that the lateral &

force exerted on the needles would pull one of the ends thereof out ofthe groove or slot and beyond the work face of the needle bed.Frequently the needles would be pulled beyond the work face of theneedle bed and into the passage between the beds to such an extent thatwhen the needle beds were racked, that is, when one needle bed was movedlongitudinally with respect to the other needle bed, the needles in theopposing needle beds would strike each other and would be bent orbroken. Attempts to solve this problem have included complicatedapparatus to separate the beds before racking and to move and hold theneedles in a retracted position in the needle beds before and during theracking operation. When-a vertical pull on the yarn is exerted at apoint recessed from the front face of the teeth 6 the necessity for thecomplicated and expensive mechanisms of the prior art no longer existssince the ends of the needles cannot be moved beyond the front face ofthe teeth 6 by the vertical pull on the yarn.

When the downward force on the needles is exerted at. a point recessedfrom the front face of the teeth 6 many novel stitches impossible offormation on knitting machines heretofore without special means aresuccessfully knitted without such means. For example, a half-cardiganstitch in the formation of which the yarn is laid into the hook of theneedle without the immediately preceeding stitch being knitted ofi theneedle and a third stitch is then knitted into the two previous stitchesis successfully knitted on a machine having needle beds embodying thepresent invention. In the formation of .a stitch of this type the firstformed stitches must be held on the needle latch while the second stitchis being formed which is the teeth 8 are made in two parts, whendesired,

each of which parts have the same configuration substantially as theteeth shown and described herein and which fit tightly together wheninserted in the grooves of the holding strip 4 to form; a single tooth.

I claim as my invention:----

1. A needle bed for a knitting machine comprising a slotted member, aholding strip removably fastened to said slotted member and a pluralityof teeth removably mounted in said holding strip, said holding striphaving a plurality of grooves therein to accommodate said teeth, each01' said teeth having a resilient, expanded portion greater in thicknessthan the width of said grooves for engaging with said strip.

2. A needle bed for a knitting machine comprising a slotted member, agrooved holding strip removably fastened to said slotted member and aplurality of resilient teeth removably mounted in the grooves of saidholding strip said teeth being held in said grooves by the frictionresulting from the resiliency thereof.

3. A needle bed for a knitting machine comprising a slotted member, agrooved holding strip removably fastened to said slotted member and aplurality of teeth removably mounted in the grooves of said holdingstrip, the part of said teeth in said grooves being resilient andpressing tightly against the sides of said grooye to hold said teeth inposition in said holding strip, another part of said teeth beingsubstantially at right angles to the part thereof in said groove andbeing in line with the ridges in said slotted member.

4. A needle bed for a knitting machine comprising a rectangular slottedmember, a holding strip removably fastened to said slotted member and aplurality of teeth removably mounted in said holding strip, each of saidteeth being perforated, the perforations in said teeth being in a lineparallel to one side of said slotted member, slightly below the level ofthe bottom of the slots therein and slightly recessed from the frontface of said teeth and a wire extending through said perforations.

5. A needle bed for a knitting machine comprising a slotted member, agrooved holding strip removably fastened to said slotted member and aplurality of teeth removably mounted in the grooves of said holdingstrip the top surface of said holding strip being in the same plane'asthe bottom surface of the slots in the slotted member, the parts of saidteeth in, said holding strip extending above the top surface thereofhaving a flared end equal in height and width to the ridges between.said slots: and being in line with said ridges. 6. A tooth fordetachable engagement with the slotted needle bed of a knitting machine,said tooth having two parts substantially at right angles to each other,one of said parts having a resilient expanded portion along its lengthfor engaging with said needle bed.

'7. A tooth for detachable en agement with the slotted needle bed of aknitting machine, said tooth being a folded member having two partssubstantially at right angles to each other, one of being perforated toaccommodate a yarn guidin no element.

CARL SCHURICI-IT.

